Locking device for fire control mechanism



July 29, 1952 A. SWIDLO LOCKING DEVICE FOR FIRE CONTROL MECHANISM Filed May 24, 1948 lvunAdirw-llflln Patented July 1952 Q UNITED; srsrss orrice LOCKING DEVICE FOR FIRE CONTROL MECHANISM lvan Swidlo, Springfield, Mass.

Application'May 24, 1948, Serial No. 28,963 1 2 Claims. (Cl. 89-149) (Granted under the act of March 3,1883, as

amemled April 30, 1928; 370 0. G. 757) 2 7 The invention described in the specification vided on operatingrod lz. A longitudinally disand claims may be manufactured and used by or posed elongated hole I"! is provided onthe forfor the Government for governmental purposes ward end of bar l4 and a headed pin [8 passin without the payment to me of any royalty through such hole is secured to receiver 10. Thus thereon. bar [4 is secured to receiver I 0 at the forward This invention relates to a device for locking end for limited longitudinalmovement. I

the firing mechanism of an automatic firearm The rear end of bar 14 is pivotally supported when the breech bolt is in the partially locked or by a link I 9. The lower end of link I 9 is pivotally unlocked position. secured to one of a pair of depending lugs 20 of In certain firearms no adequate provision is 10 receiver 19 while the upper end of link 19 is made to insure that the firing mechanism will pivotally secured to bar 54 by a pin 2!. Hammer remain safely cocked when the breech block or I3 is pivotally secured to depending lugs 20 by a bolt is in the partially unlocked position. The transverse pin 22. A stud 23 is secured to hamdangers of premature ignition, such as when the mer l3 as shown in Figs. 1 and 2 and such stud bolt is in the partially unlocked position, are well is pr v d d w th a s p surface he tr m known to those skilled in the art, for not only rear end of bar I4 is provided with a correspondmay the firearm be seriously damaged but injury ingly sloped surface 25 which is engageable with to the shooter as well may be experienced. surface 24 as shown in Fig. 2 and as will be later Accordingly it is an object of this invention described. to provide a device to lock the fire control mech- A lug 29 on bar it straddles one of the lu s anism of an automatic firearm to prevent prema- 20 of receiver l H t y Securing Such bar ture discharge of the fir rm h n th 19 11; i in against sideways displacement. A spring 26 the partially locked position. longitudinally disposed in a hole 21 provided in A particular object of this invention is to proe Te -r d of bar l a s a p ger 28 forvide a locking device for a'fire control mechawardly which bears against lug 20 of receiver l0 nism of a modified Garand type firearm thereby producing a rearward force on bar [4 The specific nature of the invention as well which tends to maintain bar l aga Operating as other objects and advantages thereof will rod !2 as shown in Fig.1.

clearly appear from a description of a preferred y t e handle por o of Operating rod embodiment as sho in th accompanying 30 i illustrated and such handle portion includes drawings in which: i a cam slot 36 which is engageable by a bolt lug Fig. 1 is a fragmentary side elevati j i roller 3! of bolt 41. Cam slot 30 is provided to of a firearm showing the fir control locking effect rotation of the firearm bolt for unlocking device with the breech elements in the battery thereof after the firing ofacartridge. position. 7 The above elements of the firearm are all con- Fig. 2 is a view similar to Fig; l but showing ventional and well known in the art and are so theoperating rod moved rearwardly just prior to described in order that the workings of this inunlockin the firearm bolt. vention about to be described can be more readily Fig. 3 is a fragmentary front end View of the understood a d p at firearm receiver showing the manner of securing To insure that firing bar M- Will e a e S thesupport member to th receiver, 23 to secure hammer [3 in the cocked position Fig. 4 i an enlarged detail perspectiveview of n the t is only partially looked, a firing the firing bar lock. bar lock 32 is provided. Such lock comprises a In Fig. l there is shown in assembled relation -l member 33 having a a portion a receiver It, a barrel H, an operating rod i2, Head portion 34 is formed integral with rod-like abolt 41 and a spring biased hammer l3 of the member 33 and is disposed at an obtuse angle well known U. S. rifle cal. .30 M1. The firing as shown in Fig. 4,while the other end of rod-like mechanism of such rifle has however been modimember 33 is sloped as shown at 35. A forwardly fied to fire either semi-automatic or full auto a d upwa d y l p partial 11018 5 s Provided matic fire. Such is largely accomplished by a in the side of receiver ll] which communicates firing bar is mounted on the side of receiver H) with cam slot 3i! provided in operating rod [2. as shown in Fig. 1 for limited longitudinal recip- Firing bar lock 32 is inserted in hole 36 so that meeting movement. An upstanding lug I5 is the sloped end 35 of rod-like member. 33 can be provided on the forward end of bar M which is engaged by a correspondingly sloped corner 31 engaged by a forwardly facing su face l 6 pro-- 5 provided on the lower forward'edge of cam slot 30 to depress such look as will be later described. A spring-like friction device 46 is longitudinally disposed on rod-like member 33 and is suitably secured thereto. Such device is utilized to retain lock 32 in hole 38 when the firearm is disassembled to prevent loss thereof.

A support member 38, which is essentially a pin, is secured to receiver to as by riveting as shown at 39 in Fig. 3 and is provided to support.

the rod-like member 33 of firing bar lock 32 not fully supported by hole 36.

end 43 engageable with a sear'shoulder. 44: pro;

vided on the end of hammer l3. The remainder of: the trigger mechanismlisnot shownbecause such mechanismforms. no part. of this invention and the workings thereof are well known to those familiar with the. U. S. rifle, calI .30IZM1. However, it is pointed outthat the triggenmechanismherein shown does. not. operate. inexactly the same manner as. only. one hammer engaging; lug is utilized, whereas in. theaforementionedl firearm twoihammer engaging lugs are employed.

The/operation of the firing bar is substantially as.fo1lows: Starting from the partially closed. batteryposition as shown in..Fig. .2,.surface. l6 Ofoperating rod. l 2-Iasshownin Fig.1 will. engage with lugv IS. on theforward movement of the firi'ngbar. l4. Insuch position. trigger.42. is. being squeezedland. its sear engaging end. 431is outof engagementwithsear shoulder 44.. Therefore; in.

its forward movement, operating rod l2 whichis actuated by a spring as known in the U. .S=-rifie-, cal. .30 M1 will pull firingbar l4 forward: and with thismovement willl'disengage sloped'su-rfacefromstud 2'3 oftheham'mer [3,..which permits.

spring biased hammer I3 to. strike thefiring pin- (not shown) When hammer. I3 is. in-the. cookedposition .and bolt 4I-is..locked.as shown-in..Fig.. 1-

and the operating rod'..l'2'..moves-. rearward; surface .31 in cam slot engages the sloped surface of lock 32 as shown in Fig. 2,. thereby forcing lock 32 downwardly into opening. and simultaneously the. head. portion v.34. of lock..3'2.. engages the rear surface-4l of. the. opening bar l4.v simultaneously withretraction of operatingrod l2, the sloped. surface 25. ofbar 14-. has been. forced onto sloped. surface 24 0f. stud.2 3i ofharnmer. l3, depressing hammer l3. slightly With forward sloped surface 35 of lock 32icoveredbybottom'surface 3T of the operating rod. l.2-.,. the. sloped surface 25' offiring, bar. I4 will. remain in. engagement with stud 23. andprevent accidental or premature release of hammer I3.while.bolt 4'! of'the firearm is in the partially lockedposition.

The above operation assumesthat thehammer I3" has been cooked by a previous reciprocation of..the-fi'rearm bolt 41. The operating rod [2. throughout. its entire. recoil stroke bears against the upper sloped" surface of lock 32 projecting through hole 36 to maintain. the head portion 34' incontact with bar I4 until'such time as operating ro'd I2 returns to battery positionwhereupon surface l6 of rod. I2 contacts lug. l5 of bar l4- to. carry such bar forwardly thereby removing, sloped end'25' from stud 23'. whereupon the hammer" maybereleasedifor firing the cartridge.

. As firing bar I'4is moved forwardly',.the rear end of such bar is pivoted downwardly a slight Firing 1 bar l4 cut 3. away as shown at 40 to accommodate support.

amount through the connection of link l9 so that sloped end 25 may break cleanly from stud 23 to insure a better releasing condition. Also when bar I4 is returned to its forward position, the surface 4! of such bar being in contact with head 34 of lock 32, forces the rod-like, member 33 forwardl'y and upwardly into cam slot 30 .as operating rod 12 goes into battery position.

Look 32 is of primary importance when the firing mechanism is set for semi-automatic fire as in: such selection of firing it is not desired to release the hammer until the proper moment as selectedby the operator. Accordingly it is highly desirable that means be provided to positively holdithe-hammer in the cooked position until its release is desired by the shooter. The firing bar lock of" this invention definitely provides that the hammer will be. positively held in the cocked position. by;means of the firing bar I4 until the bolt is fully locked.

In. full automatic firing,.the firing. lock 3.2, will insure. that. the hammer. does. not. go. forwardly prematureliyto dischargea cartridge. before the bolt. hastime to become fully locked to there.- ceiver. The operation as above described'applies to. automatic firing aswellasfor semi-automatic firing.v The only diiferencebetween. the.- tWo. is that. the sear. engaging end. 43' oil trigger 421115 held out of engagement with theh'ammer. l3j-for as longasit is-desired to fire. automatically.

It may thus be seen from thefOregoingdescriptionby those. skilled in the art that there is here provided. anunique. locking, arrangement to V. insure. that the. mechanismoffan automatic rifle of. atypeto whichthis. invention, may be applied. isin .a. safe. position. untilil the breech elements are securely locked; Such. device is. of sturdy construction and simpleand positive. in operation thus insuring'long life with aminimum replacement of component parts.

I'claimz 11111 a firearm, a, receiver, a breechb'oltreciprocable in said receiver between battery andretracted positions, an operating; rod' having, a rear- Ward endreciprocable in said'receiver from. a first forward, position for positively holdingsaid, bolt in locked battery position .rearwardly toward asecond'fposition unlocking and freeing saidbolt for. movement to retracted position, a, hammer mountedinsaid receiver for pivotal movement between cooked and firing positions,. afiring bar longitudinally movable said'receiver. between first andlsecondpositiom interengaging. means between the rearward. end. of; said firing bar and hammer, When the bar is in its said second. posi: tion, to. positively hold, said. hammer in cocked position, interengaging. means. between. the for.- ward end of said firing. bar and, said rod,.posi.- tively moving said bar. to. first position to free. said hammer by and in response toreciprocation of said rod into full first position. anupwardly-and forwardly-extending guide means in said receiver positioned between said rod andnbar, a firing, bar lockslidablein. and along said guide means'from a-firstpositionwherein theupper endof said lockis-disposed. in. the path ofsaid rod, to a-depressed position clear of said rod, and interengaging means between said bar and. lock movingsaid lock to; its said. first positionby and; in responseto movement otsaidbar to its sa-idrfirst position, saidrodmovingsaid lock and thereby said bar to. their said second; positions to hold said hammer. cockedby and -i-n response to a predetermined initiaLmovement: of: said rod-from its; said-.first position.

2,604,821 5 6 2. The firearm recited in claim 1, said rod hav- REFERENCES CITED mg a portion Wh1ch' 0n imtlal m?vement of 1 The following references are of record in the rod from first position, cams said lock into its fil of this patent; said second position and holds the same in said second position during recoil and counterrecoil 5 UNITED STATES PATENTS of said breechbolt, whereby said bar is moved into Number Name Date second position to positively hold said hammer 1,103,228 Swebilius et a1 July 14, 1914 cocked until said breechbolt has returned to and 1,110,837 Swebilius et al Sept. 15, 1914. been fully locked in battery position. 1,444,890 Swebilius Feb. 13, 1923 IVAN A. SWIDLO. 10 

